Contact Dermatitis

[mrmandrake]

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Hey guys,

I had a question on NBME 2 and it went like this:

A 14-year-old boy develops a pruritic vesicular rash on his face and hands 3 days after hiking in the woods.

Which of the following are most likely to be involved in his illness?
A) Antibody, complement C5-9
B) Circulating immune complexes, complement C5a, neutrophils
C) Cytotoxic T lymphocytes
D) IgE, mast cells, histamine, cytokines
E) Lymphocytes, cytokines, macrophages


I looked up what the consensus answer was online and it seems to be E. I read Lange Immuno though and it specifically says PPD is associated with macrophages and CD4 helper cells while contact dermatitis is associated with CD8 cytotoxic cells. Anyone know what answer is right here?

 

[SirGecko]

So the dude has a type four hypersensitivity reaction from poison ivy or something. Its E. I don't have that book so I don't know what you are reading but CD8 cells aren't involved in hypersensitivity reactions as far as I know.

Edit: So Robbins makes the point that CD8+ cells can be involved in some type IV hypersensitive autoimmune diseases. Contact Dermatitis isn't one of them though. Answer is E.

 

[gracie369]

Based on our textbook (attached) that is a BS question. Two answers could be correct.

 

[SirGecko]

Huh. As far as I know Robbins doesn't mention that and neither did my immunology text so maybe that is newer information or something? (or I just missed it) The answer they are going for is still E but I can now see how this might be confusing for people that have read that text.

 

[Step1Hash]

According to Rapid review

CD4+ = PPD/Multiple Sclerosis
CD8+ = graft vs host
CD4+ and CD8+ = contact dermatitis

so yea, BS questions.

 

[Day man]

both the review texts i've read have CD8 for contact dermatitis, it's in RR and as someone mentioned Levison. that seems like a pretty unfair question, maybe when that test came out (how long ago is that even, 4 years?) it wasn't known.

 

[mrmandrake]

Yea it seems unfair. Hopefully won't get a question like this on the real thing.